Rear brakes binding

[bluebay]

As the title say`s. I can leave home and they are fine,but after maybe 5 miles or so they start to bind,only the rears.If i leave the van and go to it the next day same story.
I`ve checked adjustment,brake cylinders all to no avail.I`ve got a new servo on.new master cylinder,goodridge flexi hoses.
I`ve just bought all new shoes so need to fix this before i fit them.
Any Ideas.
Thanks Phil.

 

[currylager]

Just a hunch, but try checking to see if the brakes are binding with the back of the van jacked up with the engine running, just to see if the servo is causing the problem. Also try driving the van with the rear brake adjusters fully backed off too see if that has any effect :roll: Any more straws to clutch anyone??

 

[Araon]

Rear stock height or lowered? bends in the flexis and rigids tight or flowing?

when you say start to bind, is it a progressively worsening bind or a constant level?

 

[bluebay]

Rear lowered, Will check flexi`s and pipes tomorrow.
not sure about it getting progresively worse, more i use the brakes maybe worse it gets. wheels are hot to touch.
Been thinking,do the hand brake cable`s tend to seize ?, holding shoes on a little getting worse as they heat up ?..

 

[Hilly_70]

I had this .. set them up fine, no binding what so ever, run around for a while and the started to bind and get very hot .. to the point of seizing solid ..

new hoses .. ( sometimes collapse internally and act as a one way valve and hold pressure into cylinders ..) , new cylinders .. everything .. still did it ..

It turned out to be the adjustment plunger into the master cylinder from the pedal was adjusted too tight and was maintaining pressure to the rear cylinders ..

Make sure the rod has a few mm play between the end of it and the inside of the cylinder ..

as soon as I loosened this the problem went away instantly ..

Hilly

 

[bluebay]

Thanks for the suggestions,
New day new enthusiasm will check out all the above and let you know.

 

[bluebay]

Checked flexi hoses,no kinks or tight spots.
Adjusted plunger rod from brake pedal to servo.
Went for run and still the same............
Gonna put it on the ramps this week and check solid pipes have not been nipped anywhere,allowing fluid past under pressure but only letting it back over time.?

thanks for the help so far.
Phil.

 

[Trikky2]

When you bled the brakes did you also bleed the pressure regulator?

 

[Hilly_70]

.... mmmm

I'd definitely change the rear flexi hoses as I have seen them look ok on the outside and 'valve' on the inside ..

Hilly

 

[bluebay]

Did not blead the pressure regulator,is there a nipple on the unit ? Would this cause the problem ?

I changed the rear flexi`s to goodridge hoses 18 months ago,so i would`nt of thought that these would be at fault yet,not at that price anyway.Has anybody had issue`s with them ?.

 

[Trikky2]

Did not blead the pressure regulator,is there a nipple on the unit ? Would this cause the problem ?

.

early bay pressure regulators normally have a bleed nipple yes - its easy to miss and surprising the black fluid that comes out when you bleed them lol

 

[bluebay]

Don`t seem to have pressure regulator,traced pipe from master cylinder to rear where it tee`s off to new braided hose then solid pipe to each brake drum.The vans a november 69,1970 model year.Has a previous owner removed it ?.
Going to remove wheels and drums tomorrow (again) and check cylinders and hand brake cable`s and adjustment.It must be something common to both as both wheels bind.As usual both wheels were free when i checked them tonight.
What am I missing ? Should I replace solid pipe from master cylinder to tee ?For the sake of a few quid ?
I`m getting frustrated with it now :evil:
Try again tomorrow.
Thanks for all the help. Phil.

 

[Trikky2]

Odd fault this.

I see you have already checked you have clearnce between the pedal operating rod and the master cylinder, since thats always a prime suspect...

If both brakes are binding its, as you say, something common

Is the brake pedal return spring ok? eg. the spring pulls the pedal right back up and doesent leave it resting against the master cylinder.

 

[bluebay]

Yes checked that,the rod returns fully.
Does anybody know what diameter the solid brake pipe is,I thik I`m gonna replace it.

 

[Trikky2]

Had another thought...

What about inside the rear drums, are they correctly assembled with the return springs in the right locations/not stretched, the slotted spacer bar correctly located between the shoes.

You could also try slackening off the handbrake cables and the re doing the brake shoe adjustment - in case the handbrake was holding the shoes instead of the adjusters.

 

[bluebay]

Not done anything tonight,too busy on home chores.Last day at work tomorrow,five days off.Will be able to get stuck into it then.Bought the brake pipe and borrowed a flaring tool,so will carry on down that route first.
Will check assembly of shoe`s etc you may be right Trikky2 I could have assembled them wrong.

 

[bluebay]

Fitted new brake pipe today,the one from the master cylinder to the tee at the rear.will bleed tomorrow and try it out.
The pipe I removed had a large loop in it I think a previous owner must have had it lying around with the ends fitted so used it on the van.Must have been 600mm too long.Fingers crossed.
Also fitted a new steering damper and fixed tie rod to try and get the steering a bit tighter.

will let you know how I get on. Phil.

 

[bluebay]

Bled the brakes today.Went for a blast,plenty of heavy braking drove around 4 miles.When I got back home both rear drums felt normal checked the front which felt the same.I thinki we may have done yippee :lol: .Will need to go for a long run to thoroughly check them out.
Thanks for all the help,will keep you posted on progress.
Phil.

 

[bluebay]

Went for a longer drive yesterday,a lot of driving around Sheffield city centre.When we got parked both rear brakes were hot again. :evil: If you`ve followed this thread you wiill read that I went out the other day with lots of heavy braking and it seemed ok.Yesterday was a lot of light braking.Below is a couple of pics of the off side brake set up.I can`t see anything wrong can you ?.Is there something obvious I just can`t see.Here`s hoping.
Phil.

 

[Trikky2]

Looked at the pics. When you took them was the handbrake off?
Reason I ask is because it looks like the handbrake is pulling. The metal plate between the top of the shoes looks like its being held off the left shoe by the drop bar.